MRC Pro Build w/ Evilinside

[Evilinside]

Ok, after asking a ton of questions on this forum, I have started my build.

I picked up a Brand New MRC Pro for $65.99 + $14.99 shipping

I decided on going brushed instead of brushless. If I could figure out how to use an Outrunner motor, I would totally go brushless, but I can't seem to dig up enough information on Outrunners for this scale to make me comfortable enough to try that combo, and I don't see any benefit of using an Inrunner over a Brushed. So I picked up a 17t double wind Contraband from Crawler Mafia and I will be mating that to a Tekin FXr Pro esc. The motor cost $60 and the Tekin cost me $119.99 for a current total of $260.97 for everything, including the MRC Pro and all shipping.

A while back I bought a DX3s from eBay. There are a couple hobby sites that have auctions for these all the time because apparently they come in a couple RC bundles, so they break apart the bundle and sell each individually. Brand new they cost 250 bucks, I was going to buy the new DX3C that just came out for $130, then I won a bid for $150 on one of those DX3S remotes, so I've been using that for all my Micro Crawlers and what not, but I have yet to use the SR3300T rx that came with it, so I'll be using that rx in this build. I know it's way over kill for this but it saves me from having to buy another rx.

I have not picked out a servo yet. I am comparing voltage drain between the servos from 1/18 scale and 1/10 scale to see if there is any big drain difference that would stop me from going with a 1/10 scale servo. So I still have not made my choice in that arena yet.

And lastly is the battery. I will probably make my own 2 cell lipo using single cell ones from HobbyKing. But that is also undetermined right now. It will be the last thing I get because once I have everything mounted into the chassis and have everything the way I want it, I will then be looking at what kind of room I have left over and therefore what kind of battery sizes I can go with.


Afterthoughts;
I'm not sure if I should be getting a BEC or not. The Tekin esc has an internal bec of 6.0V/3.0A versus getting a CC BEC that's like quadruple that.


EDIT #1:
Pictures added

[Evilinside]

Has anyone used a smaller scale servo on these pro's?

[Slaughter]

Why would you? Honestly, I haven't seen any serious builds use anything but a full size. It's going to be hard to get the torque needed from a mini servo.

[Evilinside]

Originally Posted by Slaughter

Why would you? Honestly, I haven't seen any serious builds use anything but a full size. It's going to be hard to get the torque needed from a mini servo.

Well, that's what I'm wondering. How much torque is really needed versus how much is just plain old overkill.

[Gfresh]

Originally Posted by Evilinside

Well, that's what I'm wondering. How much torque is really needed versus how much is just plain old overkill.

Lots of torque needed in a mini crawler, much more than you thing for a small rig.

I run a full size savox (low profile) at about 9kgs of torque. its just enough.

any less and I find it struggling when against rocks etc.

Depends how serious you take your crawling, a lesser servo will work (the stock is only about 3 or 4kg I think). A
Mini servos just arent as durable when running a serious mini rig.
If you have some spare servos laying around, try them and see how they go, try to gauge how much more torque is required etc.

[Evilinside]

Cool thank you!

[sickpuppy1]

Plus, if you add weight, its usually to the front. By using a full size servo you get added torque, added durability and weight on the front end. win , win , win.

[Evilinside]

Uplaoded pics to original post of what I currently have.

[ClassicGMJunkie]

i'm still using a used Hobbico CS-170 (tower pro same thing) that new is only $80, and 333 oz @ 6v. heatsinked as well. doubt you will need more or kill it on our little mrc's. anything more and you might wind up with "the tail wagging the dog" so to speak..

[Evilinside]

Originally Posted by ClassicGMJunkie

i'm still using a used Hobbico CS-170 (tower pro same thing) that new is only $80, and 333 oz @ 6v. heatsinked as well. doubt you will need more or kill it on our little mrc's. anything more and you might wind up with "the tail wagging the dog" so to speak..

Thank you!

[MRCCRAWLER1.9]

build looks good man.

[Evilinside]

Originally Posted by MRCCRAWLER1.9

build looks good man.

And thank you for the BEC lesson! I will be adding one to my "to get list".

[MRCCRAWLER1.9]

Originally Posted by Evilinside

And thank you for the BEC lesson! I will be adding one to my "to get list".

Be sure to get the Castle link 10A BEC and the Castle link. Without the castle link you will not be able to change your BEC output voltage.

[Evilinside]

Originally Posted by MRCCRAWLER1.9

Be sure to get the Castle link 10A BEC and the Castle link. Without the castle link you will not be able to change your BEC output voltage.

To answer your question from the other thread... I do not know yet what servo to get for this.

I still need to figure out the servo and the battery, then pick up that Castle Link, and I'll have everything. But I still have not been sold yet on a battery or servo...

[AreCee]

Originally Posted by Evilinside

To answer your question from the other thread... I do not know yet what servo to get for this.

I still need to figure out the servo and the battery, then pick up that Castle Link, and I'll have everything. But I still have not been sold yet on a battery or servo...

I'm using a ten year old Hitec 5925 (one of the first digitals from them) and it has about 130oz/in of torque and 0.9 sec at 6 volts. More than enough so far.

Battery: I'm using the Nano-Tech 800 2S. Fits great on the front upper links and lasts for about 20 minutes. I also have a couple G-Force 800. Good batteries for around $5 each.

Since I'm using 2S packs I am not using any external BEC, the internal BEC of the Xcelorin is more than adequate.

[MRCCRAWLER1.9]

Originally Posted by Evilinside

To answer your question from the other thread... I do not know yet what servo to get for this.

I still need to figure out the servo and the battery, then pick up that Castle Link, and I'll have everything. But I still have not been sold yet on a battery or servo...

look at valuehobby.com and their 2s 350mah bats. they seem like they wil fit the micro well..

as far as the servo goes, i would stick with hitec.

[Evilinside]

Originally Posted by AreCee

I'm using a ten year old Hitec 5925 (one of the first digitals from them) and it has about 130oz/in of torque and 0.9 sec at 6 volts. More than enough so far.

Battery: I'm using the Nano-Tech 800 2S. Fits great on the front upper links and lasts for about 20 minutes. I also have a couple G-Force 800. Good batteries for around $5 each.

Since I'm using 2S packs I am not using any external BEC, the internal BEC of the Xcelorin is more than adequate.

I couldn't find the nano-Tech 800 only the 850, could you post up the dimensions by chance?

[AreCee]

Originally Posted by Evilinside

I couldn't find the nano-Tech 800 only the 850, could you post up the dimensions by chance?

Right, it's an 850. Sorry, I was at work so I didn't remember it.

Size wise is the same as on HK's site and it fits but a smaller pack would fit easier.

[Evilinside]

Originally Posted by AreCee

Right, it's an 850. Sorry, I was at work so I didn't remember it.

Size wise is the same as on HK's site and it fits but a smaller pack would fit easier.

If you are able, would you be willing to snap a picture of that on your rig? I'd love to be able to get a visual on how that sizes up and fits in with everything!

[AreCee]

Originally Posted by Evilinside

If you are able, would you be willing to snap a picture of that on your rig? I'd love to be able to get a visual on how that sizes up and fits in with everything!

Sorry, no camera and the cell phone camera is worthless. Take a piece of cardboard and cut it to size, fold it and put it in there to size it up.
You can do that for several size packs to test fit it's like making a template.

Besides I have a custom made front end and a nonstandard servo mount so my rig isn't like yours.